1. Field of the Invention
The present invention relates to a password controlled anti-theft system which discourages theft of apparatus of a type in which entering a password sets a burglary mode in apparatus having a normal operation mode (i.e. non-burglary mode) and particularly to a system which sets and releases the burglary modes of multiple apparatuses that are connected to a central apparatus.
2. Description of the Related Art
A prior-art anti-burglar system for in-car electronic apparatus, e.g., a car-audio equipment has been known which is designed so that once the in-car electronic apparatus is removed from a car and disconnected from a backup electric power source, it will not operate even if it is again connected to an electric power source. It will only operate again when a fixed password is entered into the system, whereby the anti-burglar system produces only partial protection of the in-car apparatus.
Such burglar-proof systems operate effectively only when each of in-car electronic apparatuses has an anti-burglar system provided therein that operates independently of the other anti-burglar systems.
However, since an audio system comprising a plurality of apparatuses, e.g., an in-car multi-component stereo system is now being sold which can include C.D.'s, speakers, tape recorders, equalizers, etc., the above-described prior-art system cannot handle this audio system.
For example, in a combination of a radio receiver with a burglar-proof system and an equalizer without a burglar-proof system, releasing a burglar-proof mode of the radio receiver allows the equalizer to be freely available. Thus, the prior-art burglar-proof system has entailed a problem in that it cannot operate for the equalizer.
On the other hand, when peripheral apparatuses have respective burglar-proof system, releasing a burglar-proof mode of each peripheral apparatus by a corresponding unique method has been very complicated and in addition, providing each peripheral apparatus with a burglar-proof system is costly.